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 A002381 Numbers of the form (p^2 - 1)/120 where p is 1 or prime. (Formerly M2614 N1034) 4

%I M2614 N1034

%S 0,1,3,7,8,14,29,31,42,52,66,85,99,143,161,185,190,267,273,304,330,

%T 371,437,476,484,525,603,612,658,806,913,1015,1074,1197,1261,1340,

%U 1394,1463,1477,1548,1606,1680,1771,1912,2009,2075,2159,2262,2439,2698,2717

%N Numbers of the form (p^2 - 1)/120 where p is 1 or prime.

%C For n>1, primes p corresponding to a(n) are in A038872(n) = A045468(n-1) = A141158(n). - _Ray Chandler_, Jul 29 2019

%D H. Gupta, On a conjecture of Chowla, Proc. Indian Acad. Sci., 5A (1937), 381-384.

%D N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence).

%D N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

%H Ray Chandler, <a href="/A002381/b002381.txt">Table of n, a(n) for n = 1..10000</a>

%H H. Gupta, <a href="/A002381/a002381.pdf">On a conjecture of Chowla</a>, Proc. Indian Acad. Sci., 5A (1937), 381-384. [Annotated scanned copy]

%o (PARI) j=[]; for(n=0,150,x=prime(n)^2-1; if(Mod(x,120)==0,j=concat(j,(x/120)))); j

%Y Cf. A002382, A002855, A038872, A045468, A141158, subsequence of A093722.

%K nonn

%O 1,3

%A _N. J. A. Sloane_.

%E More terms from _Jason Earls_, Jul 29 2001

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Last modified December 10 00:54 EST 2019. Contains 329885 sequences. (Running on oeis4.)